Sign up to receive free email alerts when patent applications with chosen keywords are publishedSIGN UP

Abstract:

One aspect of the present disclosure relates to an embolic filter device
configured for placement in a blood vessel to capture emboli during a
medical procedure. The embolic filter device can include an expandable
frame member and a membrane. The expandable frame member can include a
radial support member operably connected to first and second longitudinal
struts, and an engaging portion extending between the first and second
longitudinal struts. The engaging portion can be shaped and configured to
temporarily receive, and sealingly mate with, a portion of an
endovascular catheter during the medical procedure. The membrane can be
securely connected to the frame member and define a collection chamber
for captured emboli. The membrane can be configured to cover
substantially all of the cross-sectional area of the blood vessel when
the embolic filter device is deployed in the blood vessel.

Claims:

1. An embolic filter device configured for placement in a blood vessel to
capture emboli during a medical procedure, said embolic filter device
comprising: an expandable frame member including a radial support member
operably connected to first and second longitudinal struts and an
engaging portion extending between said first and second longitudinal
struts, said engaging portion being shaped and configured to temporarily
receive, and sealingly mate with, a portion of an endovascular catheter
during the medical procedure; and a membrane securely connected to said
frame member and defining a collection chamber for captured emboli, said
membrane being configured to cover substantially all of the
cross-sectional area of the blood vessel when said embolic filter device
is deployed in the blood vessel.

2. The embolic filter device of claim 1, wherein said engaging portion is
further defined by a portion of said membrane.

3. The embolic filter device of claim 1, wherein said engaging portion
includes a plurality of filamentous members extending between said first
and second longitudinal struts.

4. The embolic filter device of claim 2, wherein said engaging portion is
further defined by a flexible rim, said flexible rim being connected to
said radial support member and a portion of said membrane that defines
said engaging portion.

5. The embolic filter device of claim 4, wherein said flexible rim
obtains an arcuate configuration upon mating with a portion of the
endovascular catheter, wherein the flexible rim has a radius of curvature
that is substantially similar to a radius of curvature of the portion of
the endovascular catheter.

6. The embolic filter device of claim 1, wherein said radial support
member includes at least one bending region configured to facilitate
collapse of said expandable frame member into a delivery catheter.

7. The embolic filter device of claim 1, further comprising a deployable
snare mechanism configured to capture the endovascular catheter and
selectively mate a portion of the endovascular catheter with said
engaging portion.

8. The embolic filter device of claim 1, further comprising an integral
adjustment mechanism configured to selectively adapt said membrane to
cover substantially all of the cross-sectional area of the blood vessel,
said integral adjustment mechanism including at least one pullwire that
is operably connected to said frame member.

9. The embolic filter device of claim 8, wherein application of a
longitudinal force to said at least one pullwire translates to a radial
force on said radial support member and thereby causes a diameter of said
radial support member to obtain a length that is about equal to a
diameter of the blood vessel.

12. An intravascular system for capturing emboli during a medical
procedure, said intravascular system comprising: an embolic filter device
comprising an expandable frame member and a membrane securely connected
to said frame member and defining a collection chamber for captured
emboli, said frame member including a radial support member operably
connected to first and second longitudinal struts and an engaging portion
extending between said first and second longitudinal struts, said
engaging portion being shaped and configured to temporarily receive, and
sealingly mate with, a portion of an endovascular catheter during the
medical procedure; and a multi-lumen delivery catheter having a plurality
of lumens, at least one of said lumens being configured to deploy said
embolic filter device.

13. The intravascular system of claim 12, wherein said multi-lumen
catheter comprises an outer lumen radially disposed about a central
lumen, said outer lumen being configured to accommodate said embolic
filter device and said central lumen being configured to accommodate a
pigtail catheter.

14. A method for capturing emboli during a medical procedure, said method
comprising the steps of: providing an embolic filter device and a
multi-lumen delivery catheter, the embolic filter device comprising an
expandable frame member and a membrane securely connected to the frame
member and defining a collection chamber for captured emboli, the frame
member including a radial support member operably connected to first and
second longitudinal struts and an engaging portion extending between the
first and second longitudinal struts, the engaging portion being shaped
and configured to temporarily receive, and sealingly mate with, a portion
of an endovascular catheter during the medical procedure; advancing the
multi-lumen delivery catheter to a deployment site in a blood vessel that
is proximate a target location; advancing the endovascular catheter to
the target location; deploying the embolic filter device from the
multi-lumen delivery catheter at the deployment site so that the engaging
portion is sealingly wrapped around a portion of the endovascular
catheter and the membrane covers substantially all of the cross-sectional
area of the blood vessel; and conducting the medical procedure.

15. The method of claim 14, wherein the medical procedure is TAVI.

16. The method of claim 14, wherein said step of advancing the
multi-lumen delivery catheter further comprises advancing a distal end of
the multi-lumen delivery catheter into a portion of an ascending aorta.

17. The method of claim 14, wherein the embolic filter device further
includes a deployable snare mechanism and said step of advancing the
embolic filter device further includes: deploying a lasso portion of the
snare mechanism; threading a portion of the endovascular catheter through
the lasso portion; and actuating the snare mechanism to capture the
endovascular catheter and mate the engaging portion with a portion of the
endovascular catheter.

18. The method of claim 17, wherein the lasso portion, upon deployment,
expands into direct contact with substantially all of the blood vessel
wall to allow passage of a medical device therethrough.

19. The method of claim 17, wherein the lasso portion extends at an angle
greater than 0.degree. relative to the multi-lumen delivery catheter upon
deployment.

Description:

RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent
Application Ser. Nos. 61/594,517, filed Feb. 3, 2012, and 61/708,180,
filed Oct. 1, 2012, the entirety of each of which is hereby incorporated
by reference for all purposes.

TECHNICAL FIELD

[0002] The present disclosure relates generally to devices and methods for
providing embolic protection in the vasculature of a subject, and more
particularly to embolic filter devices that can be deployed in a
subject's aorta to protect aortic arch vessels and downstream organs from
potential emboli.

BACKGROUND

[0003] Cerebral embolism is a known complication of cardiac surgery,
cardiopulmonary bypass, and catheter-based interventional cardiology and
electrophysiology procedures. Embolic particles, which may include
thrombus, atheroma and lipids, may become dislodged by surgical or
catheter manipulations and enter the bloodstream, embolizing in the brain
or other vital organs downstream. Other sources of potential emboli
include cardiogenic emboli, such as thrombus that results from chronic
atrial fibrillation and emboli from ruptured or vulnerable aortic plaque.
Cerebral embolism can lead to neuropsychological deficits, stroke and
even death. Other organs downstream can also be damaged by embolism,
resulting in diminished function or organ failure.

SUMMARY

[0004] One aspect of the present disclosure relates to an embolic filter
device configured for placement in a blood vessel to capture emboli
during a medical procedure. The embolic filter device can comprise an
expandable frame member and a membrane. The expandable frame member can
include a radial support member operably connected to first and second
longitudinal struts, and an engaging portion extending between the first
and second longitudinal struts. The engaging portion can be shaped and
configured to temporarily receive, and sealingly mate with, a portion of
an endovascular catheter during the medical procedure. The membrane can
be securely connected to the frame member and define a collection chamber
for captured emboli. The membrane can be configured to cover
substantially all of the cross-sectional area of the blood vessel when
the embolic filter device is deployed in the blood vessel.

[0005] Another aspect of the present disclosure relates to an
intravascular system for capturing emboli during a medical procedure. The
intravascular system can comprise an embolic filter device and a
multi-lumen delivery catheter. The embolic filter device can comprise an
expandable frame member and a membrane. The expandable frame member can
include a radial support member operably connected to first and second
longitudinal struts, and an engaging portion extending between the first
and second longitudinal struts. The engaging portion can be shaped and
configured to temporarily receive, and sealingly mate with, a portion of
an endovascular catheter during the medical procedure. The membrane can
be securely connected to the frame member and define a collection chamber
for captured emboli. The multi-lumen delivery catheter can have a
plurality of lumens, at least one of which can be configured to deploy
the embolic filter device.

[0006] Another aspect of the present disclosure relates to a method for
capturing emboli during a medical procedure. One step of the method can
include providing an embolic filter device and a multi-lumen delivery
catheter. The embolic filter device can comprise an expandable frame
member and a membrane. The expandable frame member can include a radial
support member operably connected to first and second longitudinal
struts, and an engaging portion extending between the first and second
longitudinal struts. The engaging portion can be shaped and configured to
temporarily receive, and sealingly mate with, a portion of an
endovascular catheter during the medical procedure. The membrane can be
securely connected to the frame member and define a collection chamber
for captured emboli. Next, the multi-lumen delivery catheter can then be
advanced to a deployment site in a blood vessel that is proximate a
target location. The endovascular catheter can then be advanced to the
target location. The embolic filter device can be deployed from the
multi-lumen delivery catheter at the deployment site so that the engaging
portion is sealingly wrapped around a portion of the endovascular
catheter and the membrane covers substantially all of the cross-sectional
area of the blood vessel. The medical procedure can then be conducted.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The foregoing and other features of the present disclosure will
become apparent to those skilled in the art to which the present
disclosure relates upon reading the following description with reference
to the accompanying drawings, in which:

[0008]FIG. 1A is a perspective view of an embolic filter device
constructed in accordance with one aspect of the present disclosure;

[0009]FIG. 1B is a front view of the embolic filter device in FIG. 1A;

[0010]FIG. 2A is a perspective view showing an engaging portion of the
embolic filter device in FIGS. 1A-B sealingly mated with a portion of an
endovascular catheter;

[0011]FIG. 2B is a front view of the embolic filter device and
endovascular catheter in FIG. 2A;

[0012]FIG. 3A is a perspective view showing an alternative configuration
of the embolic filter device in FIGS. 1A-B;

[0013]FIG. 3B is a perspective view showing an alternative configuration
of the embolic filter device in FIGS. 1A-B;

[0014]FIG. 4 is a perspective view showing an alternative configuration
of the embolic filter device in FIG. 3A;

[0015]FIG. 5A is a perspective view showing an alternative configuration
of a frame member comprising the embolic filter device in FIGS. 1A-B;

[0016]FIG. 5B is a perspective view showing an alternative configuration
of the frame member in FIG. 5A;

[0017]FIG. 6 is a perspective view of a magnified section of the embolic
filter device in FIG. 1B showing an alternative construction of the
engaging portion;

[0018]FIG. 7A is a perspective view showing an alternative configuration
of the embolic filter device in FIGS. 1A-B constructed in accordance with
another aspect of the present disclosure;

[0019] FIG. 7B is a front view of the embolic filter device in FIG. 7A;

[0020] FIGS. 8A-B are front views showing an alternative configuration of
an expandable frame member comprising the embolic filter device in FIGS.
1A-B;

[0021] FIGS. 8C-D are side views of the expandable frame member in FIGS.
8A-B;

[0022] FIGS. 9A-D are perspective views showing another alternative
configuration of an expandable frame member comprising the embolic filter
device in FIGS. 1A-B;

[0023]FIG. 10A is a perspective view showing an alternative configuration
of the embolic filter device in FIGS. 1A-B;

[0045]FIG. 17 is a perspective view showing an alternative configuration
of the embolic filter device in FIGS. 1A-B;

[0046]FIG. 18A is a perspective view of a multi-lumen delivery catheter
constructed in accordance with another aspect of the present disclosure;

[0047]FIG. 18B is a cross-sectional view taken along Line 18B-18B in FIG.
18A;

[0048]FIG. 18c is a perspective view showing another aspect of the
present disclosure comprising an intravascular system for capturing
emboli during a medical procedure deployed about an endovascular
catheter;

[0049]FIG. 19A is a perspective view showing an alternative configuration
of the intravascular system in FIGS. 18A-C constructed in accordance with
another aspect of the present disclosure;

[0050]FIG. 19B is a cross-sectional view taken along Line 19B-19B in FIG.
19A;

[0051]FIG. 20 is a process flow diagram illustrating a method for
capturing emboli during a medical procedure according to another aspect
of the present disclosure;

[0052]FIG. 21 is a perspective view showing the intravascular system in
FIG. 18A being deployed about an endovascular catheter in an ascending
aorta;

[0053]FIG. 22 is a perspective view showing partial deployment of the
endovascular catheter in FIG. 21;

[0054]FIG. 23 is a perspective view showing the embolic filter device of
FIGS. 1A-B deployed in the ascending aorta;

[0055]FIG. 24 is a process flow diagram illustrating another method for
capturing emboli during a medical procedure according to an aspect of the
present disclosure;

[0056] FIGS. 25A-X are a series of schematic illustrations depicting the
method in FIG. 24; and

[0057] FIGS. 26A-D are a series of perspective views showing an
alternative configuration of the intravascular system in FIGS. 19A-B
being deployed in an ascending aorta.

DETAILED DESCRIPTION

[0058] Unless otherwise defined, all technical terms used herein have the
same meaning as commonly understood by one of ordinary skill in the art
to which the present disclosure pertains.

[0059] In the context of the present disclosure, the singular forms "a,"
"an" and "the" can include the plural forms as well, unless the context
clearly indicates otherwise. It will be further understood that the terms
"comprises" and/or "comprising," as used herein, can specify the presence
of stated features, steps, operations, elements, and/or components, but
do not preclude the presence or addition of one or more other features,
steps, operations, elements, components, and/or groups thereof.

[0060] As used herein, the term "and/or" can include any and all
combinations of one or more of the associated listed items.

[0061] As used herein, phrases such as "between X and Y" and "between
about X and Y" can be interpreted to include X and Y.

[0062] As used herein, phrases such as "between about X and Y" can mean
"between about X and about Y."

[0063] As used herein, phrases such as "from about X to Y" can mean "from
about X to about Y."

[0064] It will be understood that when an element is referred to as being
"on," "attached" to, "connected" to, "coupled" with, "contacting," etc.,
another element, it can be directly on, attached to, connected to,
coupled with or contacting the other element or intervening elements may
also be present. In contrast, when an element is referred to as being,
for example, "directly on," "directly attached" to "directly connected"
to, "directly coupled" with or "directly contacting" another element,
there are no intervening elements present. It will also be appreciated by
those of skill in the art that references to a structure or feature that
is disposed "adjacent" another feature may have portions that overlap or
underlie the adjacent feature.

[0065] Spatially relative terms, such as "under," "below," "lower,"
"over," "upper" and the like, may be used herein for ease of description
to describe one element or feature's relationship to another element(s)
or feature(s) as illustrated in the figures. It will be understood that
the spatially relative terms can encompass different orientations of the
apparatus in use or operation in addition to the orientation depicted in
the figures. For example, if the apparatus in the figures is inverted,
elements described as "under" or "beneath" other elements or features
would then be oriented "over" the other elements or features.

[0066] It will be understood that, although the terms "first," "second,"
etc. may be used herein to describe various elements, these elements
should not be limited by these terms. These terms are only used to
distinguish one element from another. Thus, a "first" element discussed
below could also be termed a "second" element without departing from the
teachings of the present disclosure. The sequence of operations (or
steps) is not limited to the order presented in the claims or figures
unless specifically indicated otherwise.

[0067] It will be understood that, although the terms "first," "second,"
etc. may be used herein to describe various elements, these elements
should not be limited by these terms. These terms are only used to
distinguish one element from another. Thus, a "first" element discussed
below could also be termed a "second" element without departing from the
teachings of the present disclosure. The sequence of operations (or
steps) is not limited to the order presented in the claims or figures
unless specifically indicated otherwise.

[0068] Overview

[0069] The present disclosure relates generally to devices and methods for
providing embolic protection in the vasculature of a subject (e.g., a
human), and more particularly to embolic filter devices that can be
deployed in a subject's aorta to protect aortic arch vessels and
downstream organs from potential emboli. As representative of one aspect
of the present disclosure, FIGS. 1A-B illustrate an embolic filter device
10 configured for placement in a blood vessel to capture emboli during a
medical procedure. Although the present disclosure is described primarily
in terms of preventing emboli from entering the cerebral or peripheral
circulation during and/or after transcatheter valve implantation (TAVI),
one skilled in the art will appreciate that the present disclosure can be
employed in any medical procedure where there is a potential risk of
emboli traveling to downstream organ systems (e.g., catheter-based or
interventional procedures, such as mitral valve replacement). For
example, devices and system of the present disclosure can be deployed in
a subject to prevent or reduce of stroke, silent stroke, and other
embolic events in the brain, gut and kidneys and the peripheral
vasculature during or after surgical, minimally invasive and percutaneous
procedures, including, but not limited to transcatheter aortic valve
replacement procedures.

[0070] Devices and methods for preventing emboli during medical
procedures, such as cardiovascular interventions are known in the art.
Many of these devices merely deflect emboli from entering critical
vasculature and, moreover, fail to capture and prevent potentially lethal
emboli from lodging in vital downstream organs. Of the devices that do
capture emboli, the devices do so in specific vessels and do not protect
the overall vasculature, e.g., downstream of the ascending aorta.
Additionally, many of these devices are deployed separately from a
pigtail catheter, which is used to introduce radio-opaque contrast for
implant (e.g., a prosthetic aortic valve) confirmation. The pigtail
catheter is critical for positioning and placement of an implant as, for
example, a physician loses the means to introduce radio-opaque contrast
once the pigtail catheter is removed.

[0071] As described in more detail below, the present disclosure is
advantageously deployed in the ascending aorta and provides embolic
filter devices, systems, and methods that: (1) actually capture emboli
without merely deflecting emboli into the peripheral circulation; (2)
comprise a modified multi-lumen delivery catheter that enables both
embolic filter device deployment and radio-opaque contrast delivery
without the need for an additional access site over standard procedures;
(3) when used for TAVI, allow for device placement in the ascending aorta
to protect all three aortic branch vessels (i.e., the brachiocephalic
artery, the left common carotid artery, and the left subclavian artery),
as well as the descending aorta by mating with a portion of the
endovascular catheter (e.g., the main TAVI catheter) and covering the
cross-sectional area of the ascending aorta instead of merely covering
the ostia of the aortic branch vessels; (4) allow continued adjustment
and maneuverability of an endovascular catheter without increasing the
risk of emboli lodging in downstream organs; and (5) include various
mechanisms for quickly and efficiently capturing an endovascular
catheter, as well as ensuring that substantially all of the
cross-sectional area of a blood vessel is covered during a medical
procedure.

[0072] Devices

[0073] One aspect of the present disclosure is illustrated in FIGS. 1A-B
and includes an embolic filter device 10 configured for placement in a
blood vessel to capture emboli during a medical procedure. FIG. 1A shows
the embolic filter device 10 in a deployed configuration. In the deployed
configuration, the embolic filter device 10 has an approximately conical
configuration. The embolic filter device 10 includes a first open end 12
that is open to blood flow, and a second closed end 14 configured to
capture emboli. As described in more detail below, the portion of the
embolic filter device 10 extending between the first open end 12 and the
second closed end 14 defines a collection chamber 16 for capturing
emboli.

[0074] The embolic filter device 10 is comprised of a membrane 18 and an
expandable frame member 20 that allows the embolic filter device to be
self-supporting in the deployed configuration. The frame member 20
includes a radial support member 22 that is securely and directly
connected to at least one longitudinal strut 24. As shown in FIG. 1A, the
frame member 20 includes first and second longitudinal struts 24 and 24',
each of which is securely and directly attached to the radial support
member 22. Alternatively, the frame member 20 can include four,
non-linear or wave-like struts 24 (FIG. 3B) that allow for gradual or
staged deployment of the embolic filter device 10.

[0075] The frame member 20 has a generally wire-like or filamentous
configuration. The frame member 20 can be made of a resilient material
(e.g., stainless steel, Nitinol and/or polymer) that impart(s) the frame
member, and thus the embolic filter device 10, with the ability to
self-expand. Alternatively, the frame member 20 can be made of a
shape-memory material to facilitate deployment and/or withdrawal of the
embolic filter device 10 from the vasculature of a subject.

[0076] The radial support member 22 includes, at least in part, an
engaging portion 26 that is shaped, dimensioned, and sized to temporarily
receive, and sealingly mate with, an outer wall portion of an
endovascular catheter 28 during a medical procedure (FIGS. 2A-B). As
discussed more below, the engaging portion 28 advantageously imparts the
embolic filter device 10 with a "notch-like" structure that allows the
medical procedure to be conducted without disruption (e.g., deploying and
withdrawing multiple different catheters and filters at different stages
of the procedure). It will be appreciated that the engaging portion 26
need not make a perfect hemostatic seal with the endovascular catheter
28; rather, the only requirement is that the engaging portion should
sealingly mate with the endovascular catheter to exclude the passage of
emboli above a certain size. The engaging portion 26 extends radially
between the first and second longitudinal struts 24 and 24'. As shown in
FIG. 1A, the engaging portion 26 has a crescent shape adapted to mate
with the outer wall portion of the endovascular catheter 28. It will be
appreciated, however, that the engaging portion 26 can have any shape and
configuration sufficient to sealingly mate with an endovascular catheter
28. Thus, the engaging portion 26 can be sized and dimensioned to
accommodate a range of endovascular catheter sizes. The engaging portion
26 is also sized and configured so that movement of an endovascular
catheter 28 across the embolic filter device 10 will not jostle or
dislodge the embolic filter device. Alternative configurations of the
engaging portion 26, as well as other components of the embolic filter
device 10 are described below. As shown in FIG. 3A, for example, the
first and second longitudinal struts 24 and 24' can be disposed on
opposite ends of the engaging portion 26.

[0077] The engaging portion 26 is continuous with the remainder of the
radial support member 22. The perimeter of the radial support member 22
is generally circular, except for the engaging portion 26. In some
instances, the radius of curvature of the engaging portion 26 can be
equal, or about equal to, the radius of curvature of a portion of an
endovascular catheter 28 with which the engaging portion is temporarily
mated. For example, the engaging portion 26 can have a pre-determined
radius of curvature (e.g., based on a known radius of curvature of the
endovascular catheter 28). Alternatively, the engaging portion 26 can
have a radius of curvature that is different than the radius of curvature
of the endovascular catheter 28, but can obtain a radius of curvature
that his substantially similar to the radius of curvature of a portion of
the endovascular catheter with which the engaging portion is temporarily
mated. As described in more detail below, the portion of the radial
support member 22 that does not comprise the engaging portion 26 is sized
and configured to make a seal with a luminal surface of a blood vessel
upon deployment so that blood flow will be directed into the collection
chamber 16 to capture any emboli.

[0078] Alternative configurations of the radial support member 22 are
shown in FIGS. 4-6. As shown in FIG. 4, for example, all or only a
portion of the radial support member 22 can comprise a repeating series
of single-width cells 30 to increase the radial force of the radial
support member. The engaging portion 26 can extend substantially
perpendicular to a vertical plane P defined by the diameter of the radial
support member 22 (FIG. 5A) or, alternatively, the engaging portion can
extend substantially parallel to the vertical plane P as shown in FIG.
5B. The engaging portion 26 can additionally or optionally comprise a
series of periodic waves (FIG. 6) to locally weaken the radial stiffness
of the engaging portion and facilitate deformation of the engaging
portion about the endovascular catheter 28.

[0079] As noted above, the embolic filter device 10 (FIGS. 1A-B) comprises
a membrane 18 that is securely and directly connected to the frame member
20, which defines a collection chamber 16 for captured emboli. The
membrane 18 is supported by the frame member 20 and can be resilient,
flaccid, or plastically deformable. The membrane 18 includes a distal
peripheral edge 32 that is securely connected to a peripheral edge (not
shown in detail) of the radial support member 22. Additionally, a body
portion 34 of the membrane 18 is supported by, and connected to, at least
one longitudinal strut 24. A distal end 36 of the membrane 18 forms the
second closed end 14 of the embolic filter device 10. The membrane 18 is
configured to cover substantially all of the cross-sectional area of a
blood vessel when the embolic filter device 10 is deployed in the blood
vessel.

[0080] The membrane 18 can be made of a porous, filter mesh material
(e.g., nylon, polyurethane, PTFE, ePTFE) having a pore size chosen to
stop emboli above a certain size from passing therethrough. For example,
the membrane 18 can be made of a metal and/or polymer formed into
knitted, woven or nonwoven fiber(s), filament(s) or wire(s). The material
comprising the membrane 18 can have a pore size in the range of
approximately 1 mm to 0.1 mm or even smaller, depending on whether the
embolic filter device 10 is intended to capture macroemboli only or
microemboli as well. It will be appreciated that a portion of the
membrane 18 can alternatively be constructed of an impermeable material
rather than a porous, filter mesh material.

[0081] In some instances, the membrane 18 can include a first portion
having a first elasticity that is different than an elasticity of a
second different portion of the membrane. For example, a portion of the
membrane 12 at or near the first open end 12 can have an elasticity that
is greater than the elasticity at or near the second closed end 14. Such
a configuration may be ideal for accommodating the movement/motion at the
first open end 12 of the membrane 18 during use of the embolic filter
device 10. In such instances, the membrane 18 may be made of a single
material having two or more portions with a different respective
elasticity. Alternatively, the membrane 18 may be made of two or more
different materials, each of which can have a different elasticity. In
other instances, it will be appreciated that the membrane 18 can have a
uniform or asymmetrical pore distribution and, further, that the membrane
can include pores of the same or varying diameters.

[0082] FIGS. 7A-B illustrate another alternative configuration of the
embolic filter device 10. In some instances, the embolic filter device 10
can have a spiral-shaped configuration in the deployed configuration. In
this configuration, an S-shaped frame member 20 includes multiple
engaging portions 26 that are each sized and configured to sealingly mate
with respective portions of an endovascular catheter 28. When the embolic
filter device 10 is deployed about an endovascular catheter 28 (as shown
in FIG. 7B), a seal is formed therebetween that excludes the passage of
emboli between the frame member 20 and the endovascular catheter.
Similarly, the portion of the frame member 20 that is not in contact with
the endovascular catheter 28 makes a seal with the vessel luminal wall so
that blood flow is directed into a collection chamber 16 formed by a
membrane 18 to capture emboli.

[0083] In another aspect, alternative configurations of the expandable
frame member 20 are illustrated in FIGS. 8A-B and FIGS. 8C-D. The frame
member 20 in FIGS. 8A-B is identically constructed as the frame member in
FIGS. 8C-D, save that the radial support member 22 in FIGS. 8A-B has a
substantially O-shaped circular configuration, whereas the radial support
member in FIGS. 8C-D has a Z-shaped configuration. Although not shown, it
will be appreciated that each frame member 20 can include a membrane 18
securely affixed thereto. Additionally, each frame member 20 includes
first and second longitudinal struts 24 and 24', which, as described
below, can be comprised of one or more longitudinally extending filaments
40. Although the engaging portion 26 is generally defined by first and
second longitudinal struts 24 and 24', it will be appreciated that one or
more filaments 40 can extend (e.g., radially) between the longitudinal
struts to provide further radial support for the frame member 20.

[0084] As shown in FIGS. 8A-D, the frame member 20 can comprise one or
more diamond-shaped cells 38. Each of the diamond-shaped cells 38 can
include a plurality of flexible filaments 40 integrally formed with one
another. In some instances, each of the diamond-shaped cells 38 is
defined by the radial support member 22 (e.g., having a Z-shaped
configuration) and a series of filaments 40 having a Y-shape. In other
instances, the expandable frame member 20 can comprise one or more major
cells 42 having one or more interspersed minor cells 44. For example,
each of the major cells 42 can extend between a central connecting
portion 46 and the radial support member 22. Additionally, each of the
minor cells 44 can be disposed between two major cells 42 and be
connected at a common junction 48 with the radial support member 22. The
expandable frame member 20 is movable between a non-deployed
configuration (FIG. 8c) and a deployed configuration (FIG. 8D). The
diamond-shaped cells 38 comprising the expandable frame member 20 allow
the embolic filter device 10 to be easily collapsed and advanced through
the vasculature, while also providing a radial force sufficient to expand
the expandable frame member into contact with a blood vessel wall.

[0085] It will be appreciated that the expandable frame member 20 can
include additional features to facilitate positioning of the embolic
filter device 10 within a blood vessel. For example, the expandable frame
member 20 can include at least one bending region 50 (FIGS. 9A-D)
configured to facilitate collapse of the expandable frame member into a
delivery catheter. Advantageously, a bending region 50 can: (1) reduce or
eliminate stress points in the expandable frame member 20; and (2) allow
for apposition of the expandable frame member against different diameter
blood vessels (e.g., an aorta). In some instances, where the radial
support member 22 is comprised of a single filament or wire, a bending
region 50 can comprise a portion of the radial support member having a
tensile strength that is less than the tensile strength of the regions
immediately adjacent the bending region. Alternatively, a bending region
50 can have a different configuration where the expandable frame member
20 has a multi-part structure. For example, the expandable frame member
20 can comprise a metal (e.g., Nitinol or stainless steel) or plastic
(e.g., nylon) hypotube 52 (FIG. 9D) having a flexible filament 54 (e.g.,
a Nitinol or stainless steel wire) disposed therein. In this
configuration, the hypotube 52 can include a discontinuous region 56
bridged by the flexible filament 54, Since only the flexible filament 54
spans the discontinuous region 56 (e.g., as opposed to both the hypotube
52 and the filament), the resultant bending region 50 can impart the
expandable frame member 20 with increased flexibility at the bending
region.

[0086] In another aspect, the embolic filter device 10 can be configured
as shown in FIGS. 10A-C. For example, the embolic filter device 10 can
comprise an expandable frame member 20 including a radial support member
22 operably connected to oppositely disposed first and second
longitudinal struts 24 and 24'. The first and second longitudinal struts
24 and 24' can define an engaging portion 26 shaped and configured to
sealingly mate with a portion of an endovascular catheter 28. The embolic
filter device 10 can further include a membrane 18 securely connected to
the expandable frame member 20 and defining a collection chamber 16 for
captured emboli. In some instances, the engaging portion 26 can be
substantially free from the membrane 18. The portion of the engaging
portion 26 that is free from the membrane 18 can include an entire radial
distance r or only a portion thereof. As shown in FIGS. 10B-C, for
example, the portion of the engaging portion 26 that is free from the
membrane 18 can include a distance d that is less than the radial
distance r.

[0087] In another aspect, the engaging portion 26 (FIGS. 11A-C) can
comprise a flexible rim 58. In some instances, the flexible rim 58 can
have an arcuate shape and a radius of curvature that is equal to, or
about equal to, a radius of curvature of a portion of the endovascular
catheter 28 with which the flexible rim is temporarily mated. For
example, the flexible rim 58 can have a pre-determined radius of
curvature (e.g., based on a known radius of curvature of the endovascular
catheter 28). Alternatively, the flexible rim 58 can have a radius of
curvature that is different than the radius of curvature of the
endovascular catheter 28, but can obtain a radius of curvature that his
substantially similar to the radius of curvature of a portion of the
endovascular catheter with which the flexible rim is temporarily mated.
In other instances, the flexible rim 58 can be connected to the radial
support member 22 (e.g., disposed between the first and second
longitudinal struts 24 and 24') and a portion of the distal peripheral
edge 32 of the membrane 18.

[0088] The engaging portion 26 can also include an additional membrane
component 60, which extends between the flexible rim 58 and the first and
second longitudinal struts 24 and 24' to provide the embolic filter
device 10 with additional capacity to move and flex. The membrane
component 60 can be a continuous part of the membrane 18 itself or,
alternatively, a separate piece of material (e.g., identical to the
material used to form the membrane) that is attached (e.g., by stitching)
to the first and second longitudinal struts 24 and 24' and/or the
membrane 18. When the engaging portion 26 comprises the membrane
component 60 and/or the flexible rim 58, the engaging portion has a
notch-like or cradle-like configuration adapted to sealingly mate with a
portion of an endovascular catheter 28.

[0089] The flexible rim 58 can be elastic and impart the membrane 18 with
an additional degree of rigidity while still allowing the membrane to
expand and collapse along with the expandable frame member 20. It will be
appreciated that the engaging portion 26 shown in FIGS. 11A-B can
alternatively have a bullet-shaped configuration (FIG. 11c). For example,
the engaging portion 26 can include a first portion 62 defined by a first
distance D1 that extends between the first and second longitudinal struts
24 and 24'. The first distance D1 can be greater than a second distance
D2, which extends between the first and second longitudinal struts 24 and
24' adjacent a second portion 64 of the engaging portion 26. A tapered,
arcuate junction 66 joins the first and second portions 62 and 64 of the
engaging portion 26.

[0090] In another aspect, the embolic filter device 10 (FIGS. 12A-C) can
include an engaging portion 26 that is similar or identical to the
engaging portion shown in FIG. 11c. In some instances, the engaging
portion 26 (FIG. 12A) can further comprise a plurality of filamentous
members 68 extending between the first and second longitudinal struts 24
and 24'. The filamentous members 68 can extend substantially radial to a
longitudinal axis LA of the embolic filter device 10. Alternatively, the
filamentous members 68 can extend at an offset angle (e.g., downward or
upward) relative to the longitudinal axis LA. Each of the filamentous
members 68 can be alternately attached to the first and second
longitudinal struts 24 and 24'. The filamentous members 68 can be made of
any flexible or semi-rigid material, such as plastic or metal (e.g.,
Nitinol).

[0091] As shown in FIGS. 12B-C, the filamentous members 68 are inwardly
deformable. For example, when an endovascular catheter 28 is placed into
contact with the engaging portion 26, the filamentous members 68 can
deform inward (e.g., towards the longitudinal axis LA), which allows the
endovascular catheter to engage a central portion 70 of the expandable
frame member 20. As the endovascular catheter 28 is depressed towards the
central portion 70, all or only a portion of the filamentous members 68
may spring back to their initial orientation. Return of some or all of
the filamentous members 68 to their initial orientation can help to
ensure that the endovascular catheter 28 is securely retained within the
engaging portion 26 of the embolic filter device 10.

[0092] FIGS. 13A-D illustrate another aspect of the present disclosure
including a snare mechanism 72 configured for use with the embolic filter
device 10. As shown in FIG. 13A, the snare mechanism 72 comprises a
continuous filament 74 that is formed at one end into a lasso portion 76,
at least a portion of which is adapted to mate with an outer surface of
an endovascular catheter 28 (FIGS. 13C-D). The continuous filament 74
(FIG. 13A) can comprise a flexible wire or thread. In some instances, a
portion of the continuous filament 74 can be housed within a delivery
mechanism 78, such as a catheter. The lasso portion 76 can be selectively
enlarged and constricted by advancing or withdrawing the continuous
filament 74, respectively, through the delivery mechanism 78.

[0093] As shown in FIG. 13B, a portion of the snare mechanism 72 is
operably integrated into the embolic filter device 10. More particularly,
a portion of the continuous filament 74 can be operably embedded within a
portion of the membrane 18 at the proximal peripheral edge 80 thereof.
For example, the proximal peripheral edge 80 can be formed into a cuff
(not shown) to allow the portion of the continuous filament 74 to be
slidably received therein. As shown in FIG. 13B, the portion of the
continuous filament 74 can extend about the perimeter of the proximal
peripheral edge 80 in a substantially parallel manner with the radial
support member 22. With the snare mechanism 72 operably integrated with
the embolic filter device 10, the lasso portion 76 is oppositely disposed
from the engaging portion 26. As described in more detail below, the
snare mechanism 72 can be manipulated to selectively enlarge and contract
the lasso portion 76 (indicated by double arrow).

[0094] Operation of the snare mechanism 72 with the embolic filter device
10 is illustrated in FIGS. 13C-D. To secure the embolic filter device 10
about an endovascular catheter 28, the continuous filament 74 can first
be manipulated to enlarge the lasso portion 76. The lasso portion 76 is
enlarged to a diameter sufficient to thread the endovascular catheter 28
therethrough. As shown in FIG. 13c, for example, the lasso portion 76 is
placed over the endovascular catheter 28 and then advanced to a desired
location about the endovascular catheter.

[0095] Once the embolic filter device 10 is properly positioned about the
endovascular catheter 28, the continuous filament 74 can be manipulated
(e.g., withdrawn, as indicated by arrow) to secure the embolic filter
device thereto. More particularly, withdrawal of the continuous filament
74 causes the lasso portion 76 to cinch about the outer surface of the
endovascular catheter 28 and thereby mate the engaging portion 26 with
the endovascular catheter. The lasso portion 76 can be cinched until the
engaging portion 26 sealingly mates with the endovascular catheter 28.
Following a medical procedure, the continuous filament 74 can again be
manipulated to enlarge the lasso portion 76 and thereby allow the embolic
filter device 10 to be slidably removed from over the endovascular
catheter 28.

[0096] Another configuration of the snare mechanism 72 is illustrated in
FIGS. 15A-C. In some instances, the lasso portion 76 can comprise a
continuous filament 74 that is operably connected with the expandable
frame member 20. For example, the lasso portion 76 can be operably
disposed within the expandable frame member 20 (e.g., where the
expandable frame member comprises a hypotube 52). In other instances, a
portion of the continuous filament 74 can be housed within a delivery
mechanism (not shown), such as a delivery catheter. In this instance, the
lasso portion 76 can be selectively enlarged and constricted by advancing
or withdrawing the continuous filament 74, respectively, through the
delivery mechanism.

[0097] In operation, the continuous filament 74 can first be manipulated
to enlarge the lasso portion 76 as shown in FIG. 15A. Upon deployment,
the lasso portion 76 can expand into contact with substantially all of a
blood vessel wall (e.g., an aortic wall). The lasso portion 76 extends
away from a multi-lumen delivery catheter 82 at an angle that is greater
than 0° relative to the multi-lumen delivery catheter. In one
example, the lasso portion 76 can extend at an angle of about 90°
relative to the multi-lumen delivery catheter 82. Expansion of the lasso
portion 76 ensures that a medical device, such as an endovascular
catheter 28 can readily pass therethrough. For instance, after deploying
the lasso portion 76 in a blood vessel, an endovascular catheter 28 can
be passed through the lasso portion and advanced to a desired anatomical
location.

[0098] Once the lasso portion 76 is properly positioned about the
endovascular catheter 28, the continuous filament 74 can be manipulated
(e.g., withdrawn) to secure the embolic filter device 10 thereto. More
particularly, withdrawal of the continuous filament 74 causes the lasso
portion 76 to twist and cinch about the outer surface of the endovascular
catheter 28 and thereby mate the engaging portion 26 with the
endovascular catheter (FIG. 15B). The lasso portion 76 can then be
cinched until the engaging portion 26 sealingly mates with the
endovascular catheter 28 (FIG. 15C). Following a medical procedure, the
continuous filament 74 can again be manipulated to untwist and enlarge
the lasso portion 76 and thereby allow the embolic filter device 10 to be
slidably removed from over the endovascular catheter 28. It will be
appreciated that the snare mechanism 72 can be configured for use with
any of the embolic filter devices 10 described herein.

[0099] Although not shown, it will be appreciated that the embolic filter
device can include a dual-function snare mechanism configured to not only
capture the endovascular catheter 28 and mate the engaging portion 26
with a portion of the endovascular catheter, but also progressively close
the mouth of the collection chamber 16 following removal of the
endovascular catheter from the embolic filter device 10 but prior to
retrieving/collapsing the embolic filter device back into the multi-lumen
delivery catheter 82.

[0100] In another aspect, the expandable frame member 20 (such as the one
illustrated in FIGS. 9A-D) can include an integral adjustment mechanism
84 (FIGS. 14A-E). The integral adjustment mechanism 84 can include at
least one pullwire 86 configured to adapt the membrane 18 to cover
substantially all of the cross-sectional area of a blood vessel. As shown
in FIG. 14A, the integral adjustment mechanism 84 can include a single
pullwire 86 having a distal end 88 that is securely connected to a distal
end portion 90 of the expandable frame member 20. The pullwire 86 can
further include a proximal end (not shown) that may be manipulated by a
user (e.g., a physician) during a medical procedure. The pullwire 86 can
be made of any one or combination of materials, such as a metal (e.g.,
Nitinol or stainless steel) or a polymer (e.g., nylon). It will be
appreciated that the integral adjustment mechanism 84 can include more
than one pullwire 86, and that the pullwire(s) may be securely connected
to other portions of the expandable frame member 20.

[0101] Operation of the integral adjustment mechanism 84 is illustrated in
FIGS. 14B-E. As shown in FIG. 14B, the endovascular catheter 28 is
threaded through the lasso portion 76 of the snare mechanism 72 while the
embolic filter device 10 is in a non-deployed configuration. In the
non-deployed configuration, the membrane 18 of the embolic filter device
10 does not substantially cover the cross-sectional area of the blood
vessel (FIG. 14C). Once the embolic filter device 10 and the endovascular
catheter 28 are appropriately positioned within the blood vessel, the
pullwire 86 can be retracted (indicated by arrow) (FIG. 14D). Retracting
the pullwire 86 converts linear translational force to radial force,
which causes the expandable frame member 20 to adapt (indicated by arrow)
(FIG. 14E) and contact the blood vessel wall so that the membrane 18
substantially covers the cross-sectional area of the blood vessel. For
example, actuating the pullwire 86 generates a radial force on the radial
support member 22, which causes the diameter of the radial support member
to obtain a length that is about equal to the diameter of the blood
vessel.

[0102] It will be appreciated that the embolic filter device 10 can
include additional features to facilitate positioning of the embolic
filter device within a blood vessel. As shown in FIGS. 16A-B, for
example, the embolic filter device 10 can include at least one elongate
positioning member 92 configured to provide a counterbalancing force and
help orient the embolic filter device within a blood vessel. The at least
one elongate positioning member 92 can have a filamentous or wire-like
configuration and be made of a flexibly resilient material, such as
Nitinol, stainless steel, or a suture material. The at least one elongate
positioning member 92 can be oppositely disposed from the longitudinal
struts 24 and 24' and connected to the radial support member 22. Where
two or more elongate positioning members 92 are included as part of the
embolic filter device 10, a distal end of each of the elongate
positioning members can be connected to the radial support member 22 at a
common point or, alternatively, a distal end of each of the elongate
positioning members can be connected to the radial support member at
respectively spaced locations on the radial support member. Although not
shown in FIGS. 16A-B, it will be appreciated that the embolic filter
device 10, and in particular the distal end 36 of the membrane 18, can
additionally or optionally include an opening or exit port that permits
an elongate positioning member 92 to extend therethrough.

[0103] In another aspect, the expandable frame member 20 can include at
least one rotatable collar 94 (FIG. 17). The rotatable collar 94 can be
operably fixed to the distal end portion 90 of the expandable frame
member 20. The rotatable collar 94 can include one or more bearings (not
shown) that allow the expandable frame member 20 to be selectively
rotated by manipulating the rotatable collar. For example, the rotatable
collar 94 can be manually manipulated to adjust alignment of the engaging
portion 26 of the embolic filter device 10 with an endovascular catheter
28. Selective adjustment of the rotatable collar 94 can ensure that the
engaging portion 26 snugly contacts the endovascular catheter 28 upon
deployment of the embolic filter device 10. The rotatable collar 94 can
be made of any one or combination of biocompatible materials, such as
stainless steel, Nitinol, or a medical grade plastic.

[0104] Systems

[0105] Another aspect of the present disclosure is illustrated in FIGS.
18A-C and includes an intravascular system 96 for capturing emboli during
a medical procedure. The system 96 includes an embolic filter device 10
(as described above) and a multi-lumen delivery catheter 82 having a
plurality of lumens. The multi-lumen delivery catheter 82 is essentially
a pigtail catheter modified to include at least one lumen that is sized,
dimensioned, and configured to deploy the embolic filter device 10, and
at least one different lumen having a pigtail configuration. As shown in
FIG. 18A, the multi-lumen delivery catheter 82 includes a distal end 98
having a first opening 100 for deploying and withdrawing the embolic
filter device 10. The multi-lumen delivery catheter 82 further includes a
first lumen 102 that is integrally connected with, and extends
longitudinally about, a conventional pigtail catheter 104 having a second
lumen 106. Advantageously, the multi-lumen delivery catheter 82 enables
deployment of both the embolic filter device 10 and radio-opaque contrast
without the need for additional surgical access sites.

[0106] An alternative configuration of the intravascular system 96 is
illustrated in FIGS. 19A-C. The system 96 can include an embolic filter
device 10 and a multi-lumen delivery catheter 82. The multi-lumen
delivery catheter 82 can comprise an outer lumen 108 defined by a first
inner surface 110 and a second outer surface 112. The outer lumen 108 is
radially disposed about a central lumen 114, which is defined by a second
inner surface 116. The outer lumen 108 can be configured to accommodate
the embolic filter device 10. The central lumen 114 can be configured to
accommodate a pigtail catheter 104 such that the pigtail catheter can
move independently within the central lumen. It will be appreciated that
the lumen (not shown in detail) of the pigtail catheter 104 can be
configured to accommodate a guidewire (not shown). To permit deployment
of the pigtail catheter 104 through the embolic filter device 10, the
second end of the membrane 18 can include an opening (not shown)
configured to permit movement of the pigtail catheter therethrough.

[0107] Methods

[0108] Another aspect of the present disclosure is illustrated in FIG. 20
and includes a method 120 for capturing emboli during a medical
procedure. The method 120 is described below in terms of capturing emboli
during TAVI; however, it should be appreciated that the method can find
use in any catheter-based or interventional procedure where there is a
potential risk of emboli traveling to downstream organ systems.

[0109] One step of the method 120 includes providing an embolic filter
device 10 and a multi-lumen delivery catheter 82 (Step 122). The embolic
filter device 10 used in the method can be selected based on the type of
medical procedure being performed and, in particular, on the size and
type of endovascular catheter 28 to be used. In one example, the embolic
filter device 10 selected for the method 120 can be identically or
similarly constructed as the embolic filter device in FIGS. 1A-B. For
example, the embolic filter device 10 can comprise an expandable frame
member 20 that is securely connected to a membrane 18, which defines a
collection chamber 16 for captured emboli. The frame member 20 can
include a radial support member 22 operably connected to at least one
longitudinal strut 24. The radial support member 22 can include an
engaging portion 26 that is shaped and configured to sealingly mate with
a portion of an endovascular catheter 28. The embolic filter device 10
can be pre-loaded in the multi-lumen delivery catheter 82 (e.g., so that
the system 96 is ready for use upon removal from a packing).
Alternatively, the embolic filter device 10 can be loaded into the
multi-lumen delivery catheter 82 by a user prior to use.

[0110] At Step 124, an endovascular catheter 28 can be advanced to a
target location in a subject. As shown in FIG. 21, for example, an
endovascular catheter 28 can be advanced across the aortic arch 132 and
down through a diseased aortic valve 134. During advancement of the
endovascular catheter 28, the multi-lumen delivery catheter 82 is also
advanced to a deployment site that is proximate the target location (Step
126). For example, the distal end 118 of the multi-lumen delivery
catheter 82 is advanced to a deployment site in the ascending aorta 136
that is proximate the diseased aortic valve 134. Once the distal end 118
of the multi-lumen delivery catheter 82 is appropriately positioned at
the deployment site, radio-opaque contrast can be delivered through the
second lumen 106 of the pigtail catheter 104 to confirm the position of a
prosthetic valve (not shown).

[0111] As shown in FIG. 22, the multi-lumen delivery catheter 82 is then
slightly withdrawn prior to deploying the prosthetic valve (or before
pacing is started). Next, the embolic filter device 10 is deployed at
Step 128. The embolic filter device 10 can be progressively exuded from
the first lumen 102 of the multi-lumen delivery catheter 82 using a push
rod (not shown) or other similar mechanism capable of advancing the
embolic filter device through the first lumen towards the deployment
site. As the embolic filter device 10 emerges from the multi-lumen
delivery catheter 82, the frame member 20 self-expands into contact with
the endovascular catheter 28 and the luminal wall 138 of the ascending
aorta 136 (FIG. 23). More particularly, the engaging portion 26 of the
radial support member 22 sealingly engages a portion of the outer wall of
the endovascular catheter 28, while the remaining portion of the radial
support member forms a seal with the lumina! wall 138 of the ascending
aorta 136.

[0112] With the embolic filter device 10 fully deployed at the deployment
site, the membrane 18 substantially covers all of the cross-sectional
area of the ascending aorta 136 so that the passage of emboli of a
certain size is excluded. Additionally, the engaging portion 26 is
sealingly mated with the endovascular catheter 28 so that movement of the
endovascular catheter will not jostle or dislodge the embolic filter
device 10 and thereby risk passage of emboli into downstream organ
systems.

[0113] At Step 130, the medical procedure is conducted by replacing (or
displacing) the diseased aortic valve 134 with the prosthetic valve.
During and/or after the procedure, any emboli are captured in the
collection chamber 16 of the embolic filter device 10 and thereby
prevented from traveling through the aortic arch vessels 140 into the
cerebral circulation. Upon completion of the procedure, the embolic
filter device 10 can be collapsed into the multi-lumen delivery catheter
82 and withdrawn (along with the endovascular catheter 28) from the
subject.

[0114] Another aspect of the present disclosure is illustrated in FIG. 24
and includes a method 150 for capturing emboli during a medical
procedure. One step of the method 150 can include providing an embolic
filter device 10 and a multi-lumen delivery catheter 82 (Step 152). The
embolic filter device 10 can be pre-loaded in the multi-lumen delivery
catheter 82 (e.g., so that the system 96 is ready for use upon removal
from a packing). Alternatively, the embolic filter device 10 can be
loaded into the multi-lumen delivery catheter 82 by a user prior to use.

[0115] The method 150 can begin by gaining intravascular access at a
peripheral venous or arterial site (not shown) of a subject. As shown in
FIGS. 25A-B, a first guidewire 170 can then be inserted into the access
site and progressively urged through the vasculature of the subject until
a distal end of the first guidewire is positioned proximate a diseased
aortic valve 134. Once the first guidewire 160 is in place, an embolic
filter device 10, such as the device illustrated in FIGS. 11A-C can be
loaded into the outer lumen 108 of the multi-lumen delivery catheter 82.
As shown in FIGS. 25C-D, the multi-lumen delivery catheter 82 can then be
advanced over the first guidewire 170 into the ascending aorta 136 (Step
154). For example, the multi-lumen delivery catheter 82 can be advanced
over the first guidewire 170 by threading the first guidewire through the
central lumen 114 of the multi-lumen delivery catheter.

[0116] After the multi-lumen delivery catheter 82 is appropriately
positioned in the ascending aorta 136, the first guidewire 170 can be
withdrawn from the multi-lumen delivery catheter and removed from the
subject. A pigtail catheter 104 can then be inserted into the central
lumen 114 of the multi-lumen delivery catheter 82. As shown in FIGS.
25E-F, the pigtail catheter 104 can be advanced through the central lumen
114 until a distal end 98 of the pigtail catheter is proximate the
diseased aortic valve 134. Contrast can then be infused into the pigtail
catheter 104 and dispersed from the distal end 98 thereof to properly
image the aortic valve 134 and/or any surrounding anatomical structures.
Alternatively, both the pigtail catheter 104 and the device 10 can be
loaded together over the first guidewire 170 in the first instance and
then the first guidewire removed.

[0117] Next, the snare mechanism 72 can be deployed from the multi-lumen
delivery 82. As shown in FIGS. 25G-H, for example, deployment of the
snare mechanism 72 causes the lasso portion 76 to expand into direct
contact with substantially all of the aortic luminal wall 138 such that
the lasso portion itself is essentially perpendicular to the direction of
aortic blood flow. Once the snare mechanism 72 has been successfully
deployed, a second guidewire 172 can be inserted into the vasculature of
the subject at a surgical access site that is different than the access
site used for the first guidewire 170. The second guidewire 172 can be
advanced through the ascending aorta 136 towards the aortic valve 134
such that the second guidewire passes through the lasso portion 76 of the
snare mechanism 72 (FIGS. 25I-J).

[0118] After the second guidewire 172 is appropriately positioned, an
endovascular catheter 28, such as a balloon valvuloplasty catheter (BAV)
174 is advanced over the second guidewire as shown in FIGS. 25K-L (Step
156). With the BAV 174 threaded through the lasso portion 76, the snare
mechanism 72 is operated (e.g., pulled) so that the lasso portion 76 is
cinched about the BAV (indicated by arrows in FIG. 25N), thereby
displacing the BAV to the luminal wall 138 of the ascending aorta 136.
Next, the multi-lumen delivery catheter 82 is slightly withdrawn to
progressively free the embolic filter device 10 therefrom (FIGS. 25M-N)
(Step 158). As the embolic filter device 10 is withdrawn, the BAV 174 can
be guided into the engaging portion 26. If needed, the snare mechanism 72
can be further operated to assist in positioning the BAV 174 within the
engaging portion 26.

[0119] Following deployment of the embolic filter device 10, the pigtail
catheter 104 can be slightly withdrawn in preparation for the balloon
valvuloplasty procedure. As shown in FIGS. 25O-P, the valvuloplasty
procedure can produce emboli (indicated by empty circles) that are then
trapped by the membrane 18 of the embolic filter device 18.
Advantageously, the position of the BAV 174 in the engaging portion 26
permits the BAV to move or flex during the valvuloplasty procedure
without compromising the ability of the embolic filter device 10 to
prevent emboli from embolizing in the brain or other vital organs. After
the valvuloplasty procedure, the BAV 174 can be removed from the subject
(indicated by arrow #1) without having to remove the embolic filter
device 10. As shown in FIGS. 25Q-T, an endovascular catheter 28, such as
a TAVI catheter 176 can then be advanced through the vasculature and
mated with the engaging portion 26 (as described above). With the TAVI
catheter 176 appropriately positioned, the medical procedure can then be
conducted by replacing (or displacing) the diseased aortic valve 134 with
a prosthetic valve 178 (Step 160). During and/or after the procedure, any
emboli are captured in the collection chamber 16 of the embolic filter
device 10 and thereby prevented from traveling through the aortic arch
vessels into the cerebral circulation (FIGS. 25S-T).

[0120] Following the medical procedure, the TAVI catheter 176 can be
withdrawn from the subject (FIGS. 25U-V). If needed, the pigtail catheter
104 can be used to assess proper functioning of the prosthetic valve 178.
Additionally, if post-dilation is needed, another BAV 174 can be easily
introduced over the second guidewire 172. As shown in FIGS. 25W-X, the
second guidewire 172 can be removed from the vasculature, followed by
collapse and removal of the embolic filter device 10 (indicated by
arrows).

[0121] Another aspect of the present disclosure is illustrated in FIGS.
26A-B. As shown in FIG. 26A, the distal end 118 of the multi-lumen
delivery catheter 82 can include a pre-shaped section 142 to facilitate
deployment of a snare mechanism 72, as well as the embolic filter device
10 about an endovascular catheter 28. In some instances, the pre-shaped
section 142 of the multi-lumen delivery catheter 82 can have a sigmoid or
S-shaped configuration; however, it will be appreciated that other
configurations of the pre-shaped section are possible. With the
configuration shown in FIG. 26A, a tip 144 of the multi-lumen delivery
catheter 82 is positioned opposite an outer curvature of the ascending
aorta 136, while the remaining portion of the multi-lumen delivery
catheter is positioned immediately adjacent the outer curvature.

[0122] In operation, the multi-lumen delivery catheter 82 can first be
positioned as shown in FIG. 26A. With the multi-lumen delivery catheter
82 in place, the pigtail catheter 104 can be deployed from the central
lumen 114 of the multi-lumen delivery catheter so that the distal end 98
is adjacent the diseased aortic valve. Next, the lasso portion 76 of the
snare mechanism 72 can be progressively advanced out of the multi-lumen
delivery catheter 82 towards the outer curvature of the ascending aorta
136 (FIG. 26B). Once the lasso portion 76 is positioned as shown in FIG.
24B, the endovascular catheter 28 can be advanced through the lasso
portion (FIG. 26c). Upon threading the endovascular catheter 28 through
the lasso portion 76, the embolic filter device 10 can be deployed from
the multi-lumen delivery catheter 82. As shown in FIG. 26D, for example,
the multi-lumen delivery catheter 82 can be slightly withdrawn to allow
the embolic filter device 10 to unfurl about the endovascular catheter
28. The snare mechanism 72 can then be selectively manipulated to cinch
the lasso portion 76 and thereby guide the respective portion of the
endovascular catheter 28 into the engaging portion 26 of the embolic
filter device 10. The medical procedure can then be conducted as
described above, ensuring that any emboli captured in the collection
chamber 16 of the embolic filter device 10 are prevented from traveling
through the aortic arch vessels into the cerebral circulation.

[0123] From the above description of the present disclosure, those skilled
in the art will perceive improvements, changes and modifications. For
example, it will be appreciated that all or only a portion of the embolic
filter device 10 may be coated with an anti-thrombogenic coating, such as
a bonded heparin coating to reduce the formation of clots that could
become potential emboli. Alternatively or in addition, all or only a
portion of the embolic filter device 10 may have a drug-eluting coating
containing an anti-inflammatory or anti-stenosis agent. Such
improvements, changes, and modifications are within the skill of one in
the art and are intended to be covered by the appended claims.